authorities are warning the cold will get even worse this week. Windchill warnings stretching over 1,700 miles, from the canadian border all the way down the southern border. In indiana tonight, slow going after more snow there on top of nearly a foot of snow they had already. The famous gateway arch in st. Louis, missouri, barely visible right there in the middle of the wind. And the good samaritans, two right there helping a stranded motorist get up snow-covered ramp. Abc's gio benitez is in chicago again tonight where they have been hammered with two giant rounds of snow and the sub-zero temperatures coming. Gio, good evening. Reporter: Good evening to you, david. The snow has been falling for more than 24 hours now. And I just want to show you just how much snow there is here on this chicago sidewalk. Take a look. It's almost up to my knees. This is really the beginning of a nightmare here in the midwest. Tonight, another major snowstorm pummels the midwest. Almost a foot of snow falling today. And up next, the coldest arctic air in decades. A sub-zero cold snap hitting america's heartland. Monday's forecast? 8 below zero in cleveland. 12 below in pittsburgh. People here in chicago calling their city chi-beria. And now I'm going to buy a hat and gloves. Reporter: Yeah, you need it. City officials with the warning -- these are extremely dangerous conditions and we strongly urge people to heed the warnings and take the necessary precautions to stay safe. If you can stay indoors, please do so. Reporter: That's why minnesota's governor has already cancelled all classes monday, to keep thousands of kids at home. This is chicago's michigan avenue, that famous stopping district. You can see the water tower right there. And today, this is all packed with snow and so many shoppers looking for winter gear. In the east, ice is a problem, causing this massive 11-car pileup in new york's staten island. The concern on the roads? Black ice. That invisible ice created in below freezing temperatures. Slick roadways flipping cs on their sides. And making sidewalks slippery. The most common things are going to be ankle injuries, wrist injuries, knee and elbow. Reporter: Windchills expected to go so low in des moines, your car's antifreeze will no longer work. In minneapolis, frostbite can occur in just five minutes. And that's why tonight, people are desperately looking for ways to cover up. And cover up. We can't stress that enough. Get those ears covered. Get the hands covered. Wear those layers, david. It's really dangerous out here. And gio, our thanks to you and the crew for braving these conditions night after night for

This transcript has been automatically generated and may not be 100% accurate.

Now Playing: Deep Freeze

Now Playing: The CDC says some rapid flu tests are only 50-70% accurate

Now Playing: The Department of Veteran Affairs secretary is under growing pressure

Now Playing: A massive earthquake struck Mexico on Friday

Now Playing: A winter storm moves fast across the Northeast

Now Playing: President Trump claims vindication after new indictments in Russia probe

Now Playing: Attorneys for the alleged Parkland school shooter plead to avoid the death penalty

Now Playing: Earthquake with a preliminary magnitude of 7.2 hits Mexico

Now Playing: Trump faces allegations of a 9-month affair with a Playboy Playmate

Now Playing: FBI admits it dropped the ball after being warned about school shooting suspect

Now Playing: Winter storm warnings issued from the Rockies to the Northeast

Now Playing: At least five people were killed in a multi-vehicle crash in California

Now Playing: Flu vaccine as high as 59% effective for children 6 months to 8 years old: CDC

Now Playing: 13 Russian nationals indicted for allegedly meddling in the 2016 election

Now Playing: School massacre survivor: Every teacher should know 'that they're a hero'

Now Playing: School shooting survivor: 'Kids were bleeding out everywhere'

Now Playing: Trump to survivors of school mass shooting: 'Your suffering is our burden'

Now Playing: 5 students killed in shooting were in their 1st year of high school

Now Playing: {{itm.title}}

{"id":21429016,"title":"Deep Cold in the Deep South","duration":"3:00","description":"Dangerous cold not seen in decades as minus 50 degree wind-chill expected.","url":"/WNT/video/deep-cold-deep-south-21429016","section":"WNT","mediaType":"default"}